I really don't think it's going to help that much. Pulling two tubes - while giving you 50 watts - doesn't make much of a difference - around 3 dB. Apparently it does affect the tone according to a few seasoned Marshall players I've spoken with.

I'm not sure how the cab would affect the volume but I used to run a 100W Metaltronix at 8 ohm and it was still brutally loud.

You've got a loud amp - period !! You may want to try a Hotplate.

AL

*** quick edit ***

I read your post wrong in regards to impedance. Apologies - but I still don't think it will make much of a difference.

Well what I'm saying is if I can get a little help from each it might be enuff to make up the difference I need.

I'm actually working on it right now.

I'm pulling the two G12T-75 16 ohm Speakers and sticking in two G12 Century Vintage 8 ohm speakers.

By wiring them in series the cab will be 16 ohms then I just pull two tubes, set the ohms switch to 8 on the amp, and let her rip.

I'll report back and let you guys know what it does. I also have two G12 Century speakers but I thought I'd try the Century Vintage because they are rated 99 db and the regular Centurys are rated at 102 db. So I dont want use the louder speakers if this works. My guess is I'll like the Tonal Response of the regular Centurys better though. They are more like what came out of the cab.

Nothing wrong with that just tooo freakin loud.

If it dosent help I can allways just put it back like it was and maybe try a Hotplate next.

The amount of volume difference I want is not something I can measure. I just want it to be not as loud as it was.

Which I should say with everything I did I'm pleasently suprised. It works real well!

I changed the speakers out to be able to get the Cab at 16 ohms. I pulled the two inside Power Tubes. Also while I was inside the cab there was a brace that runs from the front of the Cab to the back. I put a screw in that through the back of the cab into it. That seems to have helped the low end boominess it had going. The speakers I put in it were the Celestion G12 Century Vintage speakers.

With the G12T-75 Speakers in it it was a tad bright and the new speakers smoothed that out just a little.

Anyway I fired it up and I'm amased at the sound I'm getting. I cant hear any Tonal Problems from pulling the two tubes. There is a small volume difference from the ohm change and the Tubes.

I can not believe how good this amp sounds. The clean sound just by rolling the volume knob on my guitar back is amasing. The dirty sound is awsome.

I'm setting the Preamp Gain full up and the Master Volume a little less than half way. This could be the ultimate giging amp with no pedals and just guitar. Then for those out side gigs just pop two more tubes in and set the ohms switch back on 16 and let her rip.

One dosent need much to play with this amp. Just a guitar and a set of fingers.

Who needs a freakin amp that cost 4 or 5 grand when you can play one of these.

Interesting thread and really coincidental. I spoke to a guy by the name of Kevin O'Conner a couple of weeks ago about his power scaling circuit. He heads up London Power and he suggested that I try pulling tubes from my amps. I got the impression that he felt that the decrease in output is not linear. I pulled a power tube out of my Deluxe Reverb and it made a huge difference in the perceived loudness of the amp to my ears while still sounding good. I have a 100W Boogie w/4 6L6's and he suggested that I could pull three tubes and be OK and that the output might go down to like 7W or so. This could only be done safely with a fixed bias amplifier.

I am not technical when it comes to this stuff but he seemed to know what he was talking about. My amp tech says that he has published a number of books on amps etc.. and he is pretty well known in the industry. This is probably old news to alot of you guys but I thought I would pass it on. I'll let you know if anything blows up but for now, everythings working.

I set a Microphone (Shure Beta 57) in front of one of the speakers in the amp and went into my Recording board.

I set the Channel it was going into so the Signal was at 0 db. Then I set the Output Level Meters from the Board Mains so it read 0 db at the loudest most Aggressive point of Playing, using some Heavey Power Chords for the Playing.

This was all done with Two Tubes Pulled (the Center two). Going into a 16 ohm cab with the ohms Selector set on 8 ohms.

Then I shut the amp off stuck the two missing Tubes back in it reset the ohms Selector to 16 ohms and fired her back up.

It was easy to see the results. The Level Meters on my Board were going to +4 db and the Level Indicator on the input of the channel was peaking red.

So I can tell a 4 db difference between the 2 and 4 Power Tubes. Also while doing this I swapped back and forth several times and did notice a Major Difference in the Loudness of the Amp.

Now you also have to bear in mind that I changed the Speakers in the Cab from 97 db 16 ohm Speakers to 99 db 8 ohm Speakers.

Its hard for me to say what difference that made because I cant switch that back and forth easy. I was trying to get the Amp to put out less with the Cab running at 16 ohms but realise the 4 db difference in the Speakers may cancel that out. As someone pointed out.

Tonight I'm gonna swap the Speakers back and see what the difference is with that, having taken a reading of the db Level before I make the swap to see if I get a difference with the ohm change and Speaker db change. I will do it four ways. 50 and 100 watt on both sets of Speakers just to check it all I can. Then I will post back my findings.